In solid-state ionology, a solid-state battery is a battery that uses solid electrodes and a solid electrolyte. Solid-state batteries generally have a lower power density and a higher energy density. Since the power and weight of solid-state batteries are relatively high, it is an ideal battery for electric vehicles.
Solid-state batteries have the inevitability of development. The solid-state battery replaces the flammable organic liquid electrolyte with a non-flammable solid-state electrolyte, which greatly improves the safety of the battery system, and at the same time can better adapt to the high-energy positive and negative electrodes and reduce the weight of the system, so as to achieve a synchronous increase in energy density. In all kinds of new battery systems, solid-state batteries are the next-generation technology closest to industrialization, which has become the consensus of the industry and the scientific community.
The industrialization stage of solid-state batteries is still in the early stages, but it is expected to develop at an accelerated speed in the future. At present, a small number of commercialized solid-state battery products have not yet formed enough competitive advantages over traditional lithium batteries, and the future solid-state batteries will take the route of stage development, gradually transitioning from special fields to power batteries, and with the accelerated layout of international giants, solid-state batteries will enter the rapid track of development.
Nowadays, most pure electric vehicles use battery packs based on lithium batteries, in which the structure is filled with electrolyte inside the battery. The electrolyte is the channel where lithium ions move back and forth, and the charge and discharge process of lithium-ion batteries is the embedding and de-embedding process of lithium ions. In the process of embedding and de-embedding of lithium ions, it is accompanied by the embedding and detachment of electrons equivalent to lithium ions. During charge and discharge, lithium ions are embedded and disconnected from the positive and negative electrodes in a cycle.
When the battery is charged, lithium ions are generated on the positive electrode, and the generated lithium ions are moved to the negative electrode through the electrolyte. The carbon as the negative electrode is a layered structure, it has many micropores, and the lithium ions that reach the negative electrode are embedded in the micropores of the carbon layer, and the more lithium ions are embedded, the higher the charging capacity.
The biggest difference between solid-state batteries and current mainstream traditional lithium-ion batteries is the electrolyte. Solid-state batteries use solid electrolytes, replacing the electrolytes and diaphragms of traditional lithium-ion batteries. The traditional lithium-ion battery is mainly composed of positive and negative electrode materials, electrolytes and diaphragms. The positive and negative electrode materials determine the capacity of the battery, and the electrolyte and diaphragm serve as a medium for transporting lithium ions.
Through this video, we will take a look at the solid-state battery:
Video source: Gem Tribe
The solid-state battery system revolution is smaller. Lithium-sulfur batteries, lithium air and other systems need to replace the entire battery structure framework, the problem is more and greater, and the solid-state battery is mainly in the innovation of the electrolyte, the positive and negative electrodes can continue to use the current system, the difficulty of realization is relatively small. Lithium metal anode compatible, achieved by solid electrolyte. Lithium sulfur and lithium air need to use lithium metal negative electrode, and lithium metal negative electrode is more likely to be realized in the solid electrolyte platform.
From the perspective of dielectric materials, the electrolytes of solid-state batteries that are currently in use or close to commercial have three kinds of polymers, sulfides and oxides, and oxide solid-state batteries are the best comprehensive prospects.
Tianfeng Securities said in a report in August last year that the advantages of oxide electrolytes are good stability, long cycle life (up to more than 1,000 times), higher energy density, better magnification performance, and lower cost; the main drawback is that the interface contact problem has not been perfectly solved.
In contrast, the industrialization of sulfide electrolytes is more difficult, and the interfacial impedance when in contact with the electrode is generally higher; polymer batteries have achieved mass production in the mobile power market, but the charging rate is poor and the energy density is low.
Looking forward to the future development trend, the technology is step by step, the application is on the ladder of penetration, and the development path of the solid-state battery stage has been clear. Structurally, at this stage, the battery system contains part of the liquid electrolyte to complement each other.commensurate. The use of liquids will be gradually reduced in the process of technological development, from semi-solid-state batteries to quasi-solid-state batteries, and finally to liquid-free all-solid-state batteries. In the field of application, it is expected to take the lead in exerting the advantages of safety and flexibility, and be applied to the field of micro batteries with less cost sensitivity, such as RFID, implantable medical devices, wireless sensors, etc.; after technological progress, it will gradually penetrate into high-end consumer batteries; with the maturity of products, it will eventually enter the electric vehicle and energy storage market on a large scale, penetrate from high-end brands downwards, and achieve a comprehensive outbreak of downstream demand.
Batteries have become a major shortcoming for many modern electronic products, including new energy vehicles. The lithium battery industry chain is an industry with good prospects for at least 10 years, and the development and rise of new technologies will continue to strengthen the valuation and prospects of the industry. Under the optimistic and multi-party layout of the industry, the solid-state battery industry is expected to achieve rapid development. Solid-state batteries carry the glorious mission of comprehensively improving battery safety and energy, and are expected to become a new flashpoint and key technical guarantee for the industry in the future.
Source: Car Corps, Wall Street News Auto, Tianfeng Securities, Auto people reference, wisdom things